AMD's RDNA 3 Will Support DisplayPort 2.0 and UHBR20

AMD
(Image credit: AMD)

AMD's upcoming Radeon RX 7000-series GPUs featuring the RDNA 3 architecture will be among the first to support full implementation of DisplayPort 2.0, which means support of up to 16K resolutions with a 60Hz refresh rate, as well as HDMI 2.1 48G, which means support of up to 10K resolutions with a 100Hz refresh rate

Linux patch discovered by @Kepler_L2 shows that at least some of AMD's next-generation Radeon RX 7000-series graphics processors featuring the RDNA 3 architecture will also feature a revamped Display Controller Next (DCN) engine that supports high data transfer for next-generation display outputs. DisplayPort 2.0's UBHR 13.5 and UHBR 20 transmission modes would likely be supported, enabling raw bandwidth of up to 54 Gbps and 80 Gbps as well as HDMI 2.1 4x12Gbps transmission rate and raw bandwidth of up to 48 Gbps. 

A DisplayPort 2.0 output supporting UHBR 20 transmission mode can handle resolutions of up to 7680×4320 at 85Hz or 10K at 60Hz with deep colors and without display stream compression (DSC) and even higher resolutions (e.g., 16K) with it. Display Port 2.0's UHBR 13.5 mode is slightly slower, but still can support an 8K HDR mode with a 60Hz refresh rate. To transmit data at 54 – 80 Gbps without errors that would render visual artifacts, DisplayPort 2.0 uses Forward Error Correction (FEC), which adds complexity to display controller and monitor's scaler. Also, one will need to use VESA-certified DP80 cables for UHBR 13.5 and UHBR 20 modes.

Swipe to scroll horizontally
Row 0 - Cell 0 Transmission ModeRaw BandwidthMaximum Display CapabilityCable Marking
DisplayPort 1.3/1.4HBR332.4 Gbps8Kp30 without DSCHBR3
DisplayPort 2.0UHBR 1040 Gbps8Kp30 without DSCDP40
DisplayPort 2.0UHBR 13.554 Gbps8Kp60 without DSCDP80
DisplayPort 2.0UHBR 2080 Gbps10Kp60 without DSCDP80

With its Ryzen RX 6000-series 'Rembrandt' APUs, AMD was the first company to partially implement VESA's DisplayPort 2.0 interface with UHRB 10 mode (10 Gbps per lane), which is enough to handle an 8K monitor with 30Hz refresh rate without DSC using a standard passive copper cable. For an APU that will power laptops as well as entry-level desktops, UHBR 10 support may be a good compromise for now, as high-performance interfaces tend to be power hungry (and there are not so many 8K monitors on the market right now) . But for high-end discrete GPUs AMD seems to be prepping a considerably more advanced and future-proof display controller with its next-generation architecture. 

In addition to DisplayPort 2.0 with UHBR 20 support, the new GPUs will also feature HDMI 2.1 4x12Gbps transmission mode (48 Gbps raw bandwidth), which means ability to handle an 8K resolution at 60Hz with HDR and 4:4:4 chroma subsampling and variable refresh rates albeit with DSC 1.2. We do not know whether AMD's next-generation HDMI 2.1 implementation supports Auto Low Latency Mode (ALLM) and Quick Frame Transport (QFT) features enabling low latency gaming.

Anton Shilov
Contributing Writer

Anton Shilov is a contributing writer at Tom’s Hardware. Over the past couple of decades, he has covered everything from CPUs and GPUs to supercomputers and from modern process technologies and latest fab tools to high-tech industry trends.

  • Tanquen
    I can't find anything conclusive on display stream compression. The folks that make it of course say it's lossy compression but that you will not be able to tell.

    What's the advantage of having DisplayPort 2.0 with more bandwidth and not having to use display stream compression? Is there added lag or a shift in color quality?

    I have the new view. Sonic 32-in elite with mini LED but it only has HDMI 2.0 ports and display port 1.4 but with display stream compression. I can max out color depth and chroma at 4K 144 Hertz and I can't tell the difference between that and turning off display stream compression in the display and maxing out a 4K 96 Hertz.

    I'd really like to see some demos and reviews on the differences, if any, and using display stream compression.

    If there is no downside, then there's no real advantage to display port 2.0. I even found that I was able to use my old cables and max out the display at 4K 144 Hertz with DSC but the cables failed with display stream. Compression turned off and trying to max out the bandwidth of the 1.4 port. I could only do 4K at 60 Hertz without getting dropouts. I did end up getting newer certified cables so I can max out the bandwidth of the 1.4 ports.
    Reply
  • Bustycat
    Tanquen said:
    I can't find anything conclusive on display stream compression. The folks that make it of course say it's lossy compression but that you will not be able to tell.

    What's the advantage of having DisplayPort 2.0 with more bandwidth and not having to use display stream compression? Is there added lag or a shift in color quality?

    I have the new view. Sonic 32-in elite with mini LED but it only has HDMI 2.0 ports and display port 1.4 but with display stream compression. I can max out color depth and chroma at 4K 144 Hertz and I can't tell the difference between that and turning off display stream compression in the display and maxing out a 4K 96 Hertz.

    I'd really like to see some demos and reviews on the differences, if any, and using display stream compression.

    If there is no downside, then there's no real advantage to display port 2.0. I even found that I was able to use my old cables and max out the display at 4K 144 Hertz with DSC but the cables failed with display stream. Compression turned off and trying to max out the bandwidth of the 1.4 port. I could only do 4K at 60 Hertz without getting dropouts. I did end up getting newer certified cables so I can max out the bandwidth of the 1.4 ports.
    Surely you don't need DP 2.0 to power your display, but it's still required for displays with a higher resolution or refresh rate. For >60 Hz with 5K, or ≥50 Hz with 8K, only DP 2.0 can power them.
    Reply
  • hotaru.hino
    Tanquen said:
    If there is no downside, then there's no real advantage to display port 2.0. I even found that I was able to use my old cables and max out the display at 4K 144 Hertz with DSC but the cables failed with display stream. Compression turned off and trying to max out the bandwidth of the 1.4 port. I could only do 4K at 60 Hertz without getting dropouts. I did end up getting newer certified cables so I can max out the bandwidth of the 1.4 ports.
    In addition to the above, it could also be useful for handling multiple DP streams out of a single DP port. Though in the gaming monitor space, this feature is rarely used for some reason.
    Reply
  • Bustycat
    hotaru.hino said:
    In addition to the above, it could also be useful for handling multiple DP streams out of a single DP port. Though in the gaming monitor space, this feature is rarely used for some reason.
    Gamers have spent thousands of dollars on a single graphics card so they cannot afford more monitors.
    Reply
  • bandit8623
    uhbr 13.5 is what they max at. wrong info on this one
    Reply